Presence and absence of sound decision device and presence and absence of sound decision manner

摘要

A voice activity detection apparatus enabling the decision ON active interval accurately regardless of time elapse is sought. Apparatus 10 comprises autocorrelation calculating unit 11 calculating autocorrelation value of input signal, delay calculating unit 12 calculating delay for calculated autocorrelation value becoming maximum, noise deciding unit 13 deciding whether input signal is noise or not based ON calculated delay, noise estimating unit 14 estimating noise from input signal and activity deciding unit 15 performing activity decision regarding input signal based ON result of decision by noise deciding unit 13, noise estimated by noise estimating unit 14, and input signal and a sound interval detecting unit 16 counting time duration of active interval based ON decision result by deciding unit 15. In case of time duration of active interval reaches a predetermined period or more and noise estimating unit 14 changes noise estimating method such that input signal is likely decided as active.